I put a set of Jug Huggers on my VTX last month. I think that they sound great! It's a much deeper sound than the Vance & Hines Big shots that I took off. Don't get me wrong the Vance & Hines pipes looked good and they were loud (but they kind of have a "motorboat sound" that I didn't care for). I am much happier with the Jug Huggers.
I have had the Jug Huggers on my 02 Retro. Next to the 2 into 1 xcellerators I believe they have the best sound. I do not believe they are the best at adding power simply because they do not have a crossover. I had the bike dyno'ed and a custom map built and the bike gave 94hp and 121ft/pd of tq with these pipes. My biggest complaint about these pipes are the fit and finish. The shields are kind of wrinkly in spots and you can see machining marks where the clamps go. They are also difficult to install as the fit is very tight between the supplied bracket and the pipe. I have since removed them and gone to V&H pipes. I kind of liked the sound but it was a very putt-putt type of sound. Just for reference the Jug Huggers are louder than the V&H pipes with the quiet baffles. I have since removed the V&H pipes (did not like the look although they are of good quality finish) because of the look as well as the shield attachment method (hose clamps). The clamps will loosen and the shield will start rattling. I now have the stock exhaust modified by JettInk and love them.
Hope this helps.
P.S. I removed the xcellerators because they were so loud they hurt my ears when travelling on the highway. They did however provide the biggest power boost and are the only exhaust pipe I have had that other people (including cagers) complimented the sound.